ALMT-independent guard cell R-type anion currents.
New Phytol
; 239(6): 2225-2234, 2023 09.
Article
em En
| MEDLINE
| ID: mdl-37434346
ABSTRACT
Plant transpiration is controlled by stomata, with S- and R-type anion channels playing key roles in guard cell action. Arabidopsis mutants lacking the ALMT12/QUAC1 R-type anion channel function in guard cells show only a partial reduction in R-type channel currents. The molecular nature of these remaining R-type anion currents is still unclear. To further elucidate this, patch clamp, transcript and gas-exchange measurements were performed with wild-type (WT) and different almt mutant plants. The R-type current fraction in the almt12 mutant exhibited the same voltage dependence, susceptibility to ATP block and lacked a chloride permeability as the WT. Therefore, we asked whether the R-type anion currents in the ALMT12/QUAC1-free mutant are caused by additional ALMT isoforms. In WT guard cells, ALMT12, ALMT13 and ALMT14 transcripts were detected, whereas only ALMT13 was found expressed in the almt12 mutant. Substantial R-type anion currents still remained active in the almt12/13 and almt12/14 double mutants as well as the almt12/13/14 triple mutant. In good agreement, CO2 -triggered stomatal closure required the activity of ALMT12 but not ALMT13 or ALMT14. The results suggest that, with the exception of ALMT12, channel species other than ALMTs carry the guard cell R-type anion currents.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Arabidopsis
/
Proteínas de Arabidopsis
Idioma:
En
Revista:
New Phytol
Assunto da revista:
BOTANICA
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Alemanha